Field
The present disclosure relates to a laser beam irradiation apparatus used to seal a substrate and a method of manufacturing an organic light-emitting display device by using the same.
Discussion of the Background
In the recent times, portable and thin flat panel display devices have increasingly been used for the displays of electronic devices. Among the flat panel display devices, electroluminescence display devices are a self-emitting type of display device having characteristics such as wide viewing angles, good contrast, and fast response times and thus attract much attention as those of the next generation display devices. Also, the organic light-emitting display devices, of which the emitting layer is formed of organic materials, are known for better luminance, driving voltage, and response time characteristics than the inorganic light-emitting display devices and can realize multicolor emission.
Generally, the organic light-emitting display devices have configurations that one or more organic layers are arranged, including an emitting layer between a pair of electrodes.
As far as the organic light-emitting display devices are concerned, when moisture or oxygen penetrates from the ambient environment to the inside of a device, the electrode materials are likely oxidized and peeled off, and for this reason, the service life of the organic light-emitting device is shortened, the emission efficiency is degraded, and the emission color is degenerated.
Therefore, in manufacturing an organic light-emitting display device, the sealing process that isolates the organic light-emitting device from the outside is generally performed in order to prevent the penetration of moisture. The conventional sealing methods include a method that laminates an organic thin film and an organic polymer, such as polyester (PET), on the second electrode of an organic light-emitting display device and a method that forms a moisture absorbent in an encapsulating substrate, charges nitrogen gas into the encapsulating substrate, and seals the edge of the encapsulating substrate with a sealant, such as epoxy.
However, because these methods have failed to prevent 100% of the degrading factors such as moisture and oxygen from penetrating from the outside, and these methods are also very complicated to implement, they could not be applied without modifications to organic light-emitting display devices that are very vulnerable to moisture. To solve such problems, a substrate-sealing method that enhances the adhesiveness between the organic light-emitting device substrate and the encapsulating substrate by using a sealant, such as frit, has been developed.
By using a structure in which the organic light-emitting display device is sealed with frit coated on a glass substrate, the space between the organic light-emitting device substrate and the encapsulating substrate is fully sealed, and thus the organic light-emitting display device can be protected more effectively.
In this method of sealing the substrate with a sealant such as frit, the frit is coated on the sealing part of the organic light-emitting display device, and a laser beam irradiation apparatus irradiates a laser beam on the sealing part of the organic light-emitting display device in motion to harden the frit, thereby sealing the substrate.